0% chance they go back to a free API. Maybe, just maybe they end up scaling back API pricing for third-party apps to something reasonable that would grant them the same revenue per user that they would get from the first-party app.
The other piece of this is that the API is also used to train AI on Reddit's data. For that application, given the colossal amount of venture capital going into AI right now, their API pricing isn't all that absurd. If Reddit were reasonable they would offer different pricing depending on what the API is going to be used for--but, then again, it's Reddit, so personally I'm throwing in my lot with FOSS.